Radio receiving system



July 2, 1929. E. HALLORAN 1,719,178

RADIO RECEIVING SYSTEM Filed Nov. lo, 1925 2 sheets-sheet l K- *BY AMK W A TTORNE Y 4July 2, 1929- F. E. HALLQRAN 1319.178

RADIO RECEIVING SYSTEM Filed Ndv. 10, 1925 2 sheets-sheet 2 A TTORNEY Patented July 2, 1929.

UNITED STATES FRANKE. HALLORAN, OF BROOKLYN, NEW YORK.

RADIO RECEIVING SYSTEM.

Application filed November 10, 1925. Serial No. 68,067. y

This invention relates to a dial control for radio receiving systems. y

Modern radio receiving systems are constructed ot parts having such electrical characteristics as to provide for extremely high selectivity in the reception `ot radiant en 'ergy. Systems of this kind usually employ combinations oit inductance and capacity, either or both ot which may be adjustably varied to bring the circuit into tune or resonance to a desired electrical frequency. Such a variable element then controls the electrical resonance` of the receiving system, and it is one object ot the present invention to provide an improved `dial control for such utilities whereby extremely tine and sensitive adjustments thereof may be readily obtained.

Another object of the invention is to provide improved adjusting means for such utilities which may be accurately readjusted to positions previously obtained, thereby to enable the operator to receive a signal at a predetermined setting of the control.

Still another object of the invention relates to an improved dial control in which back lash and lost motion is effectively minimiZed.

A feature of the invention relates to the provision et' a dial control having a plurality oi. series of4 graduations, and means for indicating thereby the adjustment of the utility, with cxtreme accuracy.

he invention is also particularly applicable to the control of a rheostat in a radio receiving system.

Other objects will appear from the following description taken in connection with the accompanying drawings in whichY Figure 1 is a diagrammatic representation oit a radio receiving system embodying ifcatures of the invention;

Figure 2 is a plan view of the dial control for the tuning element ot Figure 1; y

Figure 3 is a sectional elevation taken on the line 3 3 of Figure 2 with the gears engaged;

Figure et is a side elevation of the dial control of' Figure 2;

Figure 5 is a sectional view taken on the line 5-5 of Figure 2 with some of the gears in disengaged position;

Figure G is a plan view of a .modified form at the dial control;

Figure 7 is a sectional elevation and Figure 8 a side elevation of the dial control of Figure 6. .Y

y Like reference characters refer to like parts in the several figures of the drawings.

In the following description and claims parts will be identified by specific names for convenience of expression but they are intended to be as generic as their application to similarparts or equivalent constructions as the art will permit. i

As an aid to the understanding of the invention, there is shown in Figure 1 oi. the drawings, a diagrammatic representation ot' a typical radio receiving system embodying features of the invention. Such a receiving system includes for example, an energy coll lecting device such as an antenna 10, connected in circuit with the primary 11 of a coupling' 12 to ground 13. It is understood, however, that any other desired radiant en` ergy responsive device may be employed, such as a Belliniflossi loop. In the embodiment shown, the secondary 14 of the coupling 12 is shunted by means of a variable condenser 15 forming in combination therewith a resonant circuit 16 which may be tuned by adjustment of the condenser 15 into resonance with a desired frequency, thus render ing the receiver selectivelyresponsive to the desired signal wave. rlhe resonant circuit 16 is connected by a conductor 17 and through a blocking condenser 18 to the input or grid of a three electrode thermionic device or vacuum tube 19 having a usual {ilament 20, grid 21, and plate 22. The filament 2O is heated by means of a filament battery 23, there being included in the circuita rheostat 24 for controlling the filament current. A conductor 25 extends from one pole ot the battery 23 to the resonant circuit 16 tor completing the input circuit of the tube 19. A high resistance grid leak 26 is `provided in shunt with the blocking condenser 18. `The plate 2210i the thermionic device 19 is included in circuit with an indicating device 27 which may take the form of a telephone receiver, and with a plate potential battery 28 for rendering the plate 19 electrically positive with respect to the filament.

The parts shown in Figure 1 may bc mounted,-in a conventional manner, on a panel 30 which `'may be mounted in any desired mamar, as ttor example, mi the 'trent Vstationary plate 3l and a movable sector mounted Von a rotatable shaft 33. The shaft 33 protrudes through an a perturein the panel as shown in Figure 3 of the drawings. Similarly thev Yrheostat Q4 may be mounted on a tace of the panel 30 andmay include'a relatively viixed resistance 34 and a movable contactbrush in contact with the resistance 34. The brush is mounted on a rotatable shaft 183 one end of which protrudesthrough an. aperture in the panel -so. n y f y vReferring 4to Figures 2te 5 inclusive oi' thedrawings, there is provided a hanged metal frame 40, shown as having a pair ol' apertured lugs 41, v41 on the periphery. The trame is VatliXed on aiace of the panel 30 by suitable holding screws 42, shown as pro- .vided with hand nuts The `frame 4() is provided with afl-ange portion 44 otiset into spaced relation with the tace of the panel, in the lterm of a rack or internally toothed gear 45 (seeiliigure 2). The frame 40 thus orms etfectivelyaixed toothed gear, having a rv'prec'letermined number of teeth therein.

l Rotatably mounted Within the flange portion 44 'of theiixed gear 40 and in axial alignment therewith is a movable gear element comprising an indicatingcylinder 50, ifor'medol an`insulating"material such as a phenol compound, a metalhub 5l secured theretobyfastening'serews such as 52, and a. ring gear 53 secured tothe indicating cylinder fby fastening screws or rivets such as 54. The'hub 5liis mounted on the' end of the shaft 33 andlhas an interior recess the Vinner'ifaeeof which is screwthreaded'for a portion of itsdepth. rlhe movable ring gear 58 is provided with internal teeth and has its pitch cylinder or' the same size as the pitch .cylinder of the' iixed 'gear 40, but is provided with a different number o'l teeth.

y Preferably vthesegears differ by 011e tooth,

CTI

and in the embodiment shown the movable Vgear has al greater number of teeth than the 'loose gear. The pitch cylinders of the gears,

however, are substantially in alinement. The peripheral surface of the cylinder 50 is provided With an index,'such as the graduations 55. The frame 40 is cut away as at 56 (Figure 2)'to form a sight hole through vwhich the cylinder 50c-an be observed, and

ldesired to permit movement or"V the shaft 33 through'only180O of arc a pin 59 is inserted therein. The pin 59 contacts with the lugs 41, which thus form an abutment therefor.

purpose.

The hole 58 is so positioned that when the pin 59 is brought up against one ol the lugs 4l, the zero graduation of the cylinder reggisters, at least approximately, with the indi-x 57 on the tixed gear 40, and when the pin engages the other lng the 180" gradual ion ot' the cylinder 5t) registers, at least approximately, with the index 5T. Vl'iy withdrawing the pin, however, the shalt C323 may have a `tree movement throughout the 3Go" of are.

An indicating' dise G0, l'orined ot insulin'- ing'material, is loose-ly mounted upon the hub 5l, so :is to be rotatable with respect the-reto and wit-l1 respect to the tixed girar 40. The face of the dial (S0 may be hevelled at Gl and provided with an index such as the graduations G2. The dial is provided with an eccentrieally positioned hollow boss or projection 63, havinga shouldered bore` 64. rlhe upper end of the projection (Sil is notched and there is set in the notch so as to conform to the conligruration ol" the pro 2jection, a niet-al sleeve (i5 secured to the projection in any desired manner, as h v a pin (not shown). The outer snrl'ace. ot the sleeve is provided with an index, which may include a series ol graduations. in the here 64 is slidably mounted a pinion (57 having;` external teeth cut with the saine pitch as the teeth of' the gears l0 and 52,5, and :irranged tomesh therewith. The pinion (5T is vprovided with a shouldered hub titl ol'" irstricted diameter extending; through a cor-- respondingaperture- (59 in the dial ou and into the relatively larger bore (i4- o 1V the projection 63. rlhe outer end Tt) ot the huh 68 of the pinion is of still more restricted diameter, and there is ailixed thereto, as hv means of a pin, a button 71.` 'lhe peripheryy Yof the button is linurled, but is tiled down to a smooth. surface at one portion T2., where an ind-ex, such as a line 73 is provided` l'or a purpose which will be subsequently set forth. The top l'ace ot the button Tl is formed with a concave sui-tace, for greater convenience in operating. ',lhe hub on' is free to'slide in the aperture tit), and the pinion is normally yieldingly maintaiin-d in the position shown in Figure 23 by a coiled spring 74l positioned in the space between the Wall of the bore 64 and the hub oh', the spring presisng against the button 7l at one end. rlhe bottom of the bore (3lserves :is :in abutment for the other end of the spring'. In the normal position shown, the teeth ot' the pinion (57 engage the teeth ol' both the tixed gear 40 and the rotatable gear 53, the width of its teeth being sutlieient for this By depressing the button 7l the pinion 67 can be moved down out ot en agement with the teeth of the iixed gear 4t). The pitch cylinder of the pinion (3T is in alignment at the point where the teeth are shaft.

in mesh, `With the pitch cylinders of the `(years l0 and 53.

For maintaining the hub 51 in position on the shaft 33, there is provided a friction band. 80, formed preferably of soft rubber, adapted to fit around the Shaft 33, and Within the recess in the hub 51. A metal nipple 81, having' a bore for the shaft 33, and partially scre'wthreaded on its exterior to enrage the internal threads of the hub 51 is provided with a flange or skirt 82 to compress the friction band 80. The upper portion of the nipple 81 is provided with a hex agronal fla-nge of relatively enlarged diameter, and is held in a thumb screw 83 by means of a metal Washer having its edges ridgred so to be held in the button by being,` cramped therein, the button 83 being; preferably formed of an ii'ieulating material such ae a phenol compound. Thus` the washer turnaI with the thumb screw S3 with respect to the hub 51.

The device is assembled by mounting the pinion 67 on the indicating dise 60, and after placing theepring- 74 and the metal Sleeve in position,pinning1 the button 71 to the outer end of the pinion hub G8 with the button 71 in contact with the shoulder of the main hub 68. rl'he movable gez f and cylinder 50 are fastened together by the rivets 551, and are mounted on the hub 51 by Screws `52. The indicating disc G() 'with its pinion is then placed on the hub 51.` The friction. band 8() is inserted Within the hub 51 and the thumb Screw 83 and nipple 81 applied` so as to maintain the dial on the hub 51.

The device is mounted by elackine' eff the thumb screw 83, the zero marks of the gradnations lined up with their respective indices and held in position. The frame 4;() is then held in central. position With respect te the cylinder `5O by suitable cardboard feelere or thickness gauges, (not shown) inserted in gaa Sel, 84. The` Whole device is then set so tiat the hub 51 is on the Shaft 33 with the friction band SO around the The thumb Screw 83 then turned down so that the friction band 8O is sub jected to pressure and flows around the shaft 33, gripping it tightly. The frame 40 is fastened. to the panel 30 by vthe holding screws 112, 42 and nuts 13, and the cardboard feelers Withdrawn.

1n operation, a rough adjustment of the shaft can be obtained by placing the thumb or forefinger on the button 71 and light preseure brought te bear sufficient to overcome the tension of the `spring 711 and to meve the pinion G7 out of engagement with the lifted gear teeth 15. The indicatilm,4 disc (SO may then be rotated carryingwith it the movable gear 53, cylinder 50, hub 51 and rotating the shaft at ene-toene ratio. It will be noted that the teeth of the pinion 67 remain in constant mesh with `the teeth of the movable gear 53. rllhe index mark 57 now indicates, on the `radirations 55 of the cylinder 5() the rough adjustment of the shaft In order to obtain a more exact adjustment, the fingrer is removed from the button 71, thus allowing the pinion 67 to slide under control of the spring; P1 into en gagement with the :fixed gear teeth a5 of the fixed Igear l0. The indicating disc (50 ie then rotated backward or iirward as may be necessary, using for a handle the projection Gli. rlhe index 57 nowv registers with the grauluatione G2 on the indicatiiig disc 6() to indicate the more exact adjustment. A ratio of 91 to 1 may readily be obtained between the movement of the indicating disc 60 and the shaft using a movable gez wf 53 with 91 teeth and a fixed gear 40 with 90 teeth, by way of efe ample.'

For Still liner adjustment, the button 71 may be turned on' its own axis, and the reading taken by observing the index 73 and the girzuluations GG. ThieI movement of the pinw ion G7 causes rotation 'of the movable `{rear 53, a ratio of 341% to 1 being readily obtained by usingn a pinion having 2liteeth.

In the modified form ehown in l1 igi'nreeI G, 7 and 8 inclusive, parte are identified bythe reference numerals of `Figures 2 `to 5 inclusive, but with 10() added thereto. Thus, for example the fixed zrear of Figure 7, bearing reference numeral 14.() correeponlle to the gear Il() of Figure 3. It is thought that a brief description of the modified form will tlure'lire be ample.

Referring to Figure 7, there is showin a shaft 133 (sec Figure `1), and a fixed gear 1/10. Rotatably positioned Within the gear L10 ia a movable rear element comprising an indici-iting` cylinder 151), a hub 151 and a `ggcsar Wheel 153. The teeth ef the lined gear 1li() and of the movable gear 153 are cut with the Same cutter, with equal pitch cylinder, but the movable gear has a greater number of teeth than the fixed gear, preferably one tooth more.

j An indicating; disc 16() if; provided, with a bevelled edge, and haviru.;1 graduatimie 162.

Pivot-ally mounted on the lower face of the 1- disc le a pinion 167, in an eccentric 'position and in constant mesh With the teeth of the gears 1410, 153, and having` its teeth cut with the same cutter, and its pitch cylinder substantially in alignment therewith, at 'the peint where the teeth are in mesh.

For maintaining the hub 151 in position on the shaft `133 there is provided a friction band 181), preferably of soft rubber. A metal nipple 181 having a bore for the shaft 133, is screwed into the hub 51, and has a thumb screw 183 cramped thereto.

The mountingand operation of the modi fled form. shown n Figuree G to 8 inelneve,

will, it is thought, be clear from the foregoing description. The indicating disc 160 isV rotated to the extent necessary to obtain the desired adjust-ment. lRotation of the indicating disc moves the pinion 167 with respect to the iixed gear 140 and thus causes rotation ot the pinion on its own axis. The pinion 167 being also in mesh with the movable gear 153, the latter is' rotated causing vie the shaft 133,'to which it is secured by the compressed friction band 180, to rotate also. YVith t0 teeth in the iixed gear, il teeth in the movable gear i525 and 3i teeth in the pinion, I have obtained a very sensitive adjustment of the shaft 133.

Thus it will be seen that IA have provided a .dial control particularly suitable for highly Lsensitive radio receiving sets, which may readily be adjusted to receive a desired signal, andA which may be reset whenever desired to a desired adjustment `quickly and accurately. The dial is of simple and sturdy construction and can be readily mounted upon a panel by means oil a minimum number of holding screws and without the use of a screw .driver or wrench. rlhe movable elements of the improveddial control are fastened to the utility in a positive way, without any danger of injuring the shaft of the utility. and without throwing the shalt out oi alignment by side cramp- -ing or uneven strains.

Y The invention upon which this application is based is broader than the specii'ic embodiment shown and described for the purpose oi illustrating at least one ot the ways in which it may be employed. The scope of the invent-ioiiisV therefore to be understood as not being limited bythe piesent speciiic description. I intend no limitations other than those imposed by the claims.

What is claimed is y l. In a dial control for radiant energy receiving systems, a fixed toothed gear, a iotatable toothed gearI secured to a utility to he controlled and having an index to indicate the extent of its movement, and a pinion loosely mounted on said rotatable gear and slidable along an axis parallel to the Aaxes of said gears and having its pitch cylinder in alignment with the pitch cylinders of saidk gears.

2.` In. a dial control for radiant energy receiving systems, a fixed toothed gear, a movable gear elementsecured to a utility to be. controlled by the-dial, and a pinion selectively slidable into mesh with said gears and having its pitch cylinder in alignment with ythe pitch cylinders of said gears, and

mounted for rotation on the movable gear element so as to mesh with the teeth ol the fixed gear. V

3. In adial control for radiant energy receiving systems, a fixed toothed gear, a rotatahle toothed. Uear secured to autilt to be l E3 f controlled and having graduations thereon to indicate angular displacement thereof with respect to the tixed gear, and a pinion selectively slidable into mesh with said gears and having its pitch cylinder in alignment; with the pitch cylinders ol said gears.

Zl. In a dial control 'lor radiant energy receiving systems, a iixed toothed gear, :1. rotatable toothed gear secured to a utility to be controlled and having graduations thereon to indicate angular displacement thereof with respectto the tixed gear, and a pinion selectively slidable into mesh with said gears and having its pitch cylinder in alignment with thc pitch cylinders oi said gears.

5. In a dial control for radiant energy receiving systems, the combination ot a stationary gear having a predetermined munber oi teeth, and predetermined pitch diameter, a movable gear in axial alignment therewith and having the same pitch diameter but a relatively greater number ot teeth, and secured to the utility to be operated, a pinion slidably mounted on the movable gear, and means lor sliding said pinionto engage selectively one or both of said gears.

6. In a dial control for radiant energy receiving systems, a fixed toothed gear, a movable gear element secured to a utility to be controlled, a dial and a pinion selectively slidable into mesh with said gears and having its pitch cylinder in alignment with the pitch cylinders of said gears, and mounted for rotation on the dial so as to mesh with the teeth of the iixed gear.

7. In a dial control for radiant energy receiving systems, the combination of a stationary gear having a predetermined number of teeth, a movable gear concentrie therewith and having one more than said number of teeth, and secured to the utility to be operated, a pinion rotatably mounted on the movable gear in mesh with said stationary gear and movable longitudinally with respect thereto into a desired one olf two positions, and a yielding element. tor normally maintaining the slidable pinion in one of its positions.

8. In a dial control for radiant energy receiving systems, a fixed toothed gear, a rotatable toothed gear secured to a utility to he controlled, said gears having a relatively diii'erent number ot teeth, and having an index to indicate the extent of its movement, and a pinion longitudinally slidahle into mesh with said gears and having its pitch cylinder in alignment with the pitch cylndei's oi said gears, the teeth of said gears and said pinion having substantially the same pitch.

9. In a dial control for radiant energy receiving systems, the combination of a stationary gear liavino` a predetermined number o?? teeth and prede.ermined pitch titular-iw,

lli() lill) Hitt Cil

a movable gear in axial alignment therewith and having the same pitch dian'ieter but a relatively greater number oi? teeth and secured to the utility to be operated, a sliding pinion to engage selectively said gears, and manual means ttor sliding said pinion longitudinally.

Yl0. ln a dial control 'for radiant energy receiving systems, the combination oit a stationary gear having a predetermined number ot teeth, a movable gear concentric therewith and having one more than said number of teeth, and secured to the utility to be operated, a slidable pinion to engage selectively said gears, manually controlled means for sliding said pinion longitinlinally, and a yielding element :for normally maintaining the slidable pinion in one ot its positions.

ll. ln a dial control Afor radiant energy receiving systems, the combination of a stationary gear having a predetermined 'number ol teeth, a movable gear conceiltric therewith and having a relatively diitl'erent number oiE teeth, and secured to the utility to be operated, a dial, a pinion having an axis parallel to but spaced. lrom the aXis et said dial, said pinion being slidably mounted on the dial to engage selectively said gears, a yielding 'element :for norinally maintaining the slidable p inion in one olf its positions, and manually operable means to r moving the pinion into another of its positions.

l2. A control. device comprising a iframe having teeth to term a lixed gear and including spaced lugs whereby the frame may be inaintained in fixed position and havin a portion cut away to -form a sight hole, an indicating cylinder rotatably mounted adjacent the fixed 'frame provided with portionthereof observable through said sight hole and having a hub portion, said hub portion having a partly screwthreaded recess, a movable gear mounted on said indicating cylinder, an indicating disc rotatably mounted on said hub and having a projection cecentrically positioned thereon, a slidable pinion mounted in said projection to engage said fixed gear and said movable gear selectively, an operating button for moving said pinion, a spring mounted within said projection for maintaining said pinion normally in. one position, a friction band Within the recess of the hub for securing the indicating cylinder to the utility, and a nipple 'for maintaining said indicating disc in fixed longitudinal position and for compressing said friction band.

13. A control device cmnjnising a frame having teeth to form a lixed gear and incll'lding spaced lugs whereby the frame may he maintained in lined position and having a portion cut away to 'l'erm a sight hole, an iinlicating cylinder rotalably mounted adjacent the lixed `trame, a portion them-olfA being observable through said sight hole, and having a hub portion, said hub portion having a partly screw-threaded recess, a movable gear mounted on said :indicating cylinder, an indicating disc rotatably mounted on said hub, a pinion mounted on said disc to engage said :lixed gear and said movable gear, a friction band within the recess oit the hub for securing the indicating cylinder to the utility, and a nipple :tor maintaining said indicating disc in lixed longitudiiml position and for compressing said 'liriotigm band.

l-t. A control device comprising a frame having teeth to form a fixed gear and including spaced lugs whereby the frame may he maintained in liXed position and having a portion cut away to iform a sight hole, an indicating cylinder rotatably mounted adjacent the fixed trame, said cylinder being observable through said sight hole, and having a hub portion, said hub portion having a partly screwthreaded recess, a. movable gear mounted on said. indicating` cylinder, a separable stop member carried by said cylinder so as to Contact with said lugs to limit the movement ot the cylinder with respect to the xed frame, an indicating disc rotatably mounted on said hub and having a projection eccentrically positioned thereon, a slidable pinion .mounted in said projection to engage said fixed gear and said movable gear selectively,` an operating button lor moving said pinion, a spring mounted within said projection for maintaining said pinion normally in one position, a friction band within the recess olf: the hub for securing the indieating cylinder to the utility, and a nipple for uraintaining said indicating disc in lixed longitudinal position and tor comjn'essing said friction band.

Signed at New York, in the county of New York and State oil" New York, this ninth day of November, A. D. 1925.

FRANK E. HALLORAN. 

